Good stuff i will call you rabbi I can only try
like everything else it’s a machlakos, as far as the gemarah if masser applied outside e”y the gemarah would have answered the question as such. “why are ppl wealthy outside e”y? answer they give masser as well” if masser on money is an obligation that would have been the answer even if they were talking about things that grow.
the following hold it’s not a darrasa 1) maharil tshuva 54 as well as 56, 2) rav chaim yosef david azulai, 3) rav yechiel michal epstein. others hold it’s just a minhag 1) rav meir rothenburg teshuva 131, 2) rav yoel sirkes, 3) dayan weiss, 4) rav shlomo zalman auerbach.
for the record i always say bli neder so i can stop if c”v i have to.
on a side note ppl don’t realize masser and tzedaka are 2 different things, tzedaka is darrasa and an absolute must, but not masser.
ps if according to thoise that holds masser is darrasa why isn’t the promise coming true? the promise is we won’t be able to say stop enough times, even the wealthy ppl are not THAT wealthy!! and you can’t say anything that will include 100% of klay yisroel, there is no one now or ever before that was so wealthy they said enough already!